Revision 5b7aa38d86f348847a48f71e9ac7715406de900e authored by Hao Xu on 22 September 2021, 10:12:38 UTC, committed by Jens Axboe on 24 September 2021, 16:24:34 UTC
For multishot mode, there may be cases like: iowq original context io_poll_add _arm_poll() mask = vfs_poll() is not 0 if mask (2) io_poll_complete() compl_unlock (interruption happens tw queued to original context) io_poll_task_func() compl_lock (3) done = io_poll_complete() is true compl_unlock put req ref (1) if (poll->flags & EPOLLONESHOT) put req ref EPOLLONESHOT flag in (1) may be from (2) or (3), so there are multiple combinations that can cause ref underfow. Let's address it by: - check the return value in (2) as done - change (1) to if (done) in this way, we only do ref put in (1) if 'oneshot flag' is from (2) - do poll.done check in io_poll_task_func(), so that we won't put ref for the second time. Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> Link: https://lore.kernel.org/r/20210922101238.7177-4-haoxu@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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File | Mode | Size |
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Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | -rw-r--r-- | 16.6 KB |
.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
.gitattributes | -rw-r--r-- | 62 bytes |
.gitignore | -rw-r--r-- | 1.9 KB |
.mailmap | -rw-r--r-- | 19.8 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 98.6 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 605.7 KB |
Makefile | -rw-r--r-- | 64.0 KB |
README | -rw-r--r-- | 727 bytes |
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